The H-1 to H-4 trails loop is a classic circuit in Thunderbird Conservation Park, a 1,185-acre desert preserve set in the Hedgpeth Hills on the north side of Glendale, Arizona. The park is dedicated to protecting and showcasing the Sonoran desert environment, and it packs roughly 20 miles of multiuse trails into its hills, all within easy reach of the Phoenix metro. For hikers and mountain bikers on the west side of the valley, it's the local go-to.

The H-designated trails form the backbone of the network, and stringing them together makes for a genuinely good outing. The popular Cholla Loop, for instance, follows the H1 trail along the base of the hill to the northeast, then climbs the ridge on switchbacks before returning to the trailhead via the H3 trail, hugging the base of the hill back to the southeast. That circuit runs about 3.5 miles, rates as moderately difficult, and suits most skill levels including families and active beginners, climbing saguaro-dotted hills to a ridge with an excellent view over the city before dropping back down.

The wider park offers plenty more. The Coach Whip, Ridgeline and Sunrise Loop is the single most popular route here, holding an average of about 4.6 stars across more than 3,400 reviews, while the Three Peaks Loop packs the most climbing at roughly 1,407 feet of ascent for those wanting a workout. The trails are shared by hikers, runners and mountain bikers, so a bit of courtesy at blind corners goes a long way.

One current note worth checking before you drive out: the park is working through parking lot and trailhead improvements, with the 59th Avenue lot closed from April 2026 into December 2026, the 55th Avenue lot from August 2026 into February 2027, and the 67th Avenue lot from January 2027 into August 2027. All trails remain open throughout, but the lot you plan to use may not be. Checking the City of Glendale's park page before setting out saves a frustrating arrival.

This is low desert, and heat governs everything. Summer means hiking at first light or not at all, while October through April is genuinely lovely, with wildflowers in spring and comfortable temperatures. Shade is nonexistent on the ridges.

Come with plenty of water, sun protection, and shoes with grip for the rocky tread; watch for rattlesnakes in the warm months. For 20 miles of saguaro-covered desert hills with city views, free and ten minutes from Glendale, Thunderbird is a genuine asset.